有机粘土矿物对污染环境修复的研究进展

本文综述了国外在有机粘土矿物对污染环境修复研究方面的最新进展，具体介绍了利用表面活性剂制备有机粘土矿物的方法，不同类型有机粘土矿物的特征，有机粘土矿物对各种有机污染物的吸附行为及机理，在地下水污染的现场修复，土地填埋防渗添加材料和去除工业废水有机污染物等方面的应用。     

Bioaccumulation of organochlorine contaminants in fish species from Lake Qarun,a protected area of Egypt

The purpose of this study was to determine concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Nile tilapia (Oreochromis niloticus) and Bouri fish (Mugil cephalus) from Lake Qarun, a protected area of Egypt, and evaluate the relative ecological risk of these compounds. Different tissues of the fish species were analyzed for 26 chlorinated pesticides and 29 PCB congeners. Total concentrations (µg/kg wet weight, ww) of OCPs ranged between 1487 and 6217 (mean: 3260) and of PCBs between 9.0 and 61 (mean: 34). The trend of detected organochlorine pollutants was: endrin aldehyde > dieldrin > hexachlorobenzene > PCBs > endrin > 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethanes (DDTs). Heptachlor epoxide; oxy-, cis-, and trans-chlordane; trans-nonachlor; β-hexachlorocyclohexane; δ-hexachlorocyclohexane; and endosulfan I and endosulfan sulfate levels were below the detection limit. The ratios of (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylenes [DDEs] + 1,1-dichloro-2,2-bis(p-chlorophenyl)ethanes [DDDs])/ΣDDTs in fish tissues indicated no recent DDT exposure. Concentrations of DDTs and PCBs were generally comparable or higher than those found in studies of similar species worldwide. The concentrations of hexachlorobenzene, dieldrin, and endrin aldehyde in fish muscles exceeded the maximum residue level recommended by various organizations.     

Persistent of Organochlorine Pesticides in the Green Lip Mussel (Perna Viridis) From Marine Estuaries in Thailand

Thailand has benefited from the availability of pest control chemicals for improving agricultural products and in public health like any other developing countries. in order to understand the distribution and contamination in the Gulf of Thailand, a Mussel Watch programme has been set up to monitor trace toxic substances of organochlorine pesticides along the Gulf of Thailand since 1989.

This paper focuses on the concentration of organochlorine pesticides in green lip mussels (Perna viridis) during 1989 to 1996. the mussel samples were used as a biological indicator and analyzed for 23 organochlorine compounds. the highest frequencies of organochlorine pesticide residues in Thailand were found in aldrin, dieldrin and DDTs in all samples and the highest concentration of DDT-isomer were p,p'-DDE and p,p'-DDT during 1989-1990 and 1991. the p,p'-DDE was only found during 1993-1995.

In 1996 the level of the DDT isomer (o,p-DDE) were found in the range of 11-16ppb(ngg^-1 wet weight), HCH isomer (a-HCH) was found ND -1.6ppb(ngg^-1 wet weight) and cis-chlordane found at ND - 3.4 ppb(ngg^-1 wet weight). Other organoichlorine pesticide compounds such as dieldrin, heptachlor, aldrin, endrin and endosulfan isomers were not detected. the detection limit of all organochlorine compounds were 1.3-8.2ppb(ngg^-1 wet weight). Trends of organochlorine pesticide residue in this area were found differently from the previous data during 1989-1991.     

Sorption of heavy metals in strongly weathered soils: an overview

Current knowledge of sorption processes in tropical soils is reviewed. Landscapes throughout the tropics are dominated by oxisols which occupy extensive areas of potentially highly productive soils. These soils are dominated by low-activity sesquioxide minerals and clays that have variable charge surfaces. The limited information on tropical soils available suggests that the composition of the ambient soil solution can influence sorption through changes in particle surface-charge density. Thus the observed decrease in sorption in the presence of divalent index cations may be related to the effect of ionic charge on the double-layer thickness which is manifested through a change in surface-charge characteristics. However, much work needs to be done to differentiate the effect of cation charge on surface-charge density from the competitive effect between the index cation and heavy-metal ions for the sorption sites. The effects of inorganic and organic ligands on adsorption of Cd by variable charge surfaces are also reviewed.     

Influence of destructive bacteria and red clover (trifolium pratense L.) on the pesticides degradation in the soil

Environmental Geochemistry and Health - Lindane and DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) are pesticides from the group of persistent organic pollutants. These compounds, due to...     

The concentration and distribution of organochlorine pesticides in the air from the karst cave, South China

Organochlorine pesticides (OCPs) in the air of Dayan Cave in Guilin were analyzed, to investigate the source and contamination levels. Generally, air outside of the cave had much higher concentrations than inside air, and both outside and inside air showed much lower contamination levels than those observed in other regions in China and abroad. The ratios of α-/γ-HCHs and the percentages of β-(or δ-)HCH implied a residue of historical local technical HCH contamination. The DDT concentrations, o,p'-DDT/p,p'-DDT, and p,p'-DDE/p,p'-DDT suggested fresh DDT-containing products acted as the primary source of DDT for the air in Dayan Cave. An intermediate level concentration of α-endosulfan (156.00?pg/m(3)) was observed in the outside air, implying local source was dominant. Based on the similar sources of HCH and DDT and the relationships between outside and inside air, it appeared that outside air pollutants affected on inside HCH and DDT's distribution. For other OCPs, outside air might be major contributor to inside air contamination under conditions of high concentrations in outside air compared with low levels in inside air for semi-closed karstic caves.     

Effect of Ca(II), Fe(II), and Fe(III) on Cu(II) adsorption by a polyvinylidene fluoride-based chelating membrane from Cu(II)–EDTA complex solution

A polyvinylidene fluoride-based membrane bearing the diethylenetriaminepentaacetic acid chelating group was employed to recover Cu(II) from the Cu(II)-ethylenediaminetetraacetic acid complex aqueous solution. Effects of Ca(II), Fe(II), and Fe(III) on Cu(II) uptake were investigated by static batch adsorption tests and dynamic adsorption filtration. Isotherms, kinetics, and breakthrough curves of Cu(II) uptakes in the presence of the three cations at concentrations of 1 mmol L^?1 were elucidated. The three cations showed a positive effect on the Cu(II) uptake; the stimulative roles were in the order of Fe(III) > Fe(II) > Ca(II). They did not alter the adsorption behavior of the membrane; adsorption isotherms and kinetics could be described by Langmuir and Lagergren second-order models, and Cu(II) adsorption was a spontaneous and exothermic process. The presence of Ca(II), Fe(II), and Fe(III) increased the sorption capacity of the membrane stack by 1.3, 1.9, and 3 times. Breakthrough time and the exhaustion time of membrane stacks were also extended.     

p,p'-DDE与雄激素受体突变体H874Y及T877A激动性作用机制的理论研究

1,1-二氯-2,2-双(对氯苯基)乙烯(p,p'-DDE)是一种已知的雄激素受体(androgen receptor,AR)拮抗剂。有趣的是,已有研究证实p,p'-DDE同时可经由作用于AR的2种天然突变体H874Y和T877A产生拟雄激素效应,但其相互作用的分子机制尚不清晰。本研究联用分子动力学模拟与MM-GBSA方法,以内源性激素二氢睾酮(DHT)作为对照,对p,p'-DDE与2种突变体的相互作用分子机制进行了研究。模拟结果指出范德华相互作用是维持p,p'-DDE与AR突变体结合的主要驱动力,而溶剂化作用的差异是导致p,p'-DDE与H874Y具有较高结合活性的主要原因,H874Y结合口袋与p,p'-DDE的结构匹配度优于与T877A。与内源性配体二氢睾酮相比较,范德华作用与静电相互作用的差异是造成p,p'-DDE比DHT结合活性低的主要原因,p,p'-DDE与AR突变体之间缺乏氢键的稳定。MM-GBSA的结果确定p,p'-DDE与突变体结合过程的关键氨基酸以疏水性残基为主,其中L704、M745、L873尤为重要。计算获得的p,p'-DDE对H874Y及T877A相互作用分子机制有助于理解该污染物在不同人群中内分泌干扰效应的差异。     

TMA改性粘土矿物对模拟地下水中苯系物的吸附

用短链季铵盐阳离子表面活性剂四甲基铵离子（ＴＭＡ）改性膨润土和凹凸棒土,研究它们对模拟地下水中苯系物的吸附作用。二种ＴＭＡ改性粘土矿物均可以有效地吸附模拟地下水中的苯系物,吸附机理较复杂,主要以表面吸附为主。     

土壤中铅的吸附-解吸行为研究进展

铅是重要的土壤重金属污染元素之一，了解铅在土壤中的物理化学行为，有利于预防和修复土壤的铅污染。土壤中铅的吸附-解吸行为，依吸附机理的不同，分为专性吸附和非专性吸附。土壤铅吸附的机理还存在不同的观点，如水解吸附／非水解吸附机理，单分子吸附／双分子吸附机理等。影响土壤中铅吸附-解吸行为的主要因素，有土壤矿物组成、土壤有机质、pH、温度、竞争离子等。文章最后对描述土壤铅吸附过程的主要数学方程(Langmuir方程、Freundlich方程和Temkin方程)作了论述。     

Antioxidant enzyme activities of <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis> in response to nonylphenols and degradation of nonylphenols by <Emphasis Type="Italic">M. aeruginosa</Emphasis>

The aim of this study was to examine the effects of chemical nonylphenols (NPs) on the antioxidant system of Microcystis aeruginosa strains. The degradation and sorption of NPs by M. aeruginosa were also evaluated. High concentrations of NPs (1 and 2 mg/l) were found to cause increases in superoxidase dismutase (SOD) and glutathione-S-transferase (GST) activities and in glutathione (GSH) levels. These results suggest that toxic stress manifested by elevated SOD and GST levels and GSH contents may be responsible for the toxicity of NPs to M. aeruginosa and that the algal cells could improve their antioxidant and detoxification ability through the enhancement of enzymatic and nonenzymatic prevention substances. The observed elevations in GSH levels and GST activities were relatively higher than those in SOD activities, indicating that GSH and GST contributed more in eliminating toxic effects than SOD. Low concentrations of NPs (0.05–0.2 mg/l) enhanced cell growth and decreased GST activity in algal cells of M. aeruginosa, suggesting that NPs may have acted as a protecting factor, such as an antioxidant. The larger portion of the NPs (>60%) disappeared after 12 days of incubation, indicating the strong ability of M. aeruginosa to degrade the moderate persistent NP compounds. The sorption ratio of M. aeruginosa after a 12-day exposure to low nominal concentrations of NPs (0.02–0.5 mg/l) was relatively high (>30%). The fact that M. aeruginosa effectively resisted the toxic effects of NPs and strongly degraded these pollutants indicate that M. aeruginosa cells have a strong ability to adapt to variations in environmental conditions and that low and moderate concentrations of organic compounds may favor its survival. Further studies are needed to provide detailed information on the fate of persistent organic pollutants and the survival of algae and to determine the possible role of organic pollutants in the occurrence of water blooms in eutrophic lakes.     

土壤和沉积物中非水解有机碳对菲的吸附

采用改进的酸水解方法对土壤和沉积物中的有机质组分进行了分离和提取,用固体13C核磁共振（13CNMR）表征了非水解有机碳（NHC）,同时研究了不同有机质组分对菲的吸附行为,结果表明,菲的吸附等温线都呈现出明显的非线性,能很好地拟合Freundlich方程;而且NHC和碳黑（BC）比其原始和去矿样品的吸附容量都有明显提高.这些结果揭示了NHC和BC主要控制着菲在土壤和沉积物中的吸附行为.沉积物及其NHC对菲的吸附容量要高于土壤及其NHC,这与土壤和沉积物中有机质的不同来源有关.     

沉积物对菲和五氯酚的吸附性能

研究了菲和五氯酚（PCP）在五种沉积物的吸附解吸行为，菲和PCP在各沉积物上的吸附和解吸都是较快的过程。均能在8h内达到平衡，吸附和解吸结果表明，高有机质含量的沉积物对菲和PCP的吸附和持留能力都较强，菲和PCP在各沉积物中的吸附系数跟沉积物的有机质含量呈线性正相关。等温吸附结果表明，低有机质含量的三种沉积物比有机质含量较高的两种沉积物呈更好的线性关系。不同沉积物对菲和PCP的吸附性能差异跟沉积物的有机质含量密切相关。     

添加羟基磷灰石对土壤铅吸附与解吸特性的影响

采用羟基磷灰石对四种不同类型的土壤进行铅的吸附-解吸试验.结果表明:四种土壤对铅的吸附均可用Langmuir和Freundlich方程进行描述,土壤中加入羟基磷灰石明显增加了土壤对铅的吸附量和吸附亲和力,同时降低了土壤中铅的解吸百分数,在偏酸性的红壤上表现更为明显,其最大吸附量增加28%.羟基磷灰石对铅吸附的反应机理可能与磷灰石溶解后与铅形成磷酸盐沉淀及其对铅的表面吸附作用有关.土壤对铅的吸附量及吸附亲和力与土壤的有机质、阳离子交换量及粘粒含量有显著正相关,而与土壤砂粒的含量呈负相关.     

全氟辛烷磺酸盐(PFOS)对半滑舌鳎(Cynoglossus semilaevis)免疫相关基因表达的影响

为了解全氟辛烷磺酸盐(perfluorooctane sulfonate, PFOS)暴露对半滑舌鳎(Cynoglossus semilaevis)免疫功能的影响,在实验室条件下,运用RT-PCR方法分析了PFOS暴露对半滑舌鳎热休克蛋白hsp70、hsp90、C型凝集素(c-type lectin)和细胞色素c氧化酶(cytochrome c oxidase, cox)等4种免疫相关基因表达水平的影响。实验测定了上述4种基因在半滑舌鳎肝、鳃、肠及肌肉4种不同组织中随时间(0、24 h、48 h、96 h和7 d)的表达变化情况。结果表明,在4种组织中,hsp70基因的表达与对照相比为上调,其中,肝组织hsp70基因的表达量显著高于其他各组织,且表达高峰值的出现也早于其他各组织;hsp90基因在肝和鳃组织中表达量随时间不同而波动,在肠组织中表达上调,在肌肉中表达显著下调;c-type lectin基因表达量与对照组相比表达显著下调或无明显差异;cox基因在肝组织和肠组织中表达下调,在鳃和肌肉中表达上调。上述研究结果表明,PFOS能引起免疫相关基因的表达变化,对半滑舌鳎具有潜在的免疫毒性。肝组织中各免疫基因对PFOS胁迫的响应高于其他组织。本研究可为阐明全氟辛烷磺酸盐对半滑舌鳎的免疫毒性提供基础数据。     

土壤与沉积物对多环芳烃类有机物的吸附作用

吸附作用是疏水性有机物在土壤和沉积物环境中的重要迁移转化行为之一。多环芳烃是环境中一种重要的疏水性有机污染物。文章着重阐述了多环芳烃类有机物在土壤和沉积物中有机质和粘土矿物吸附机理，指出土壤、沉积物有机质的结构异质性是导致非线形吸附的重要原因；分析了影响多环芳烃吸附过程的诸多因素，并提出该研究领域存在的问题以及今后发展的方向。     

Enhanced debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by zero-valent zinc with ascorbic acid

• Highly efficient debromination of BDE-47 was achieved in the ZVZ/AA system. • BDE-47 debromination by the ZVZ/AA can be applied to a wide range of pH. • AA inhibits the formation of (hydr)oxide and accelerates the corrosion of ZVZ. • Reduction mechanism of BDE-47 debromination by the ZVZ/AA system was proposed. A new technique of zero-valent zinc coupled with ascorbic acid (ZVZ/AA) was developed and applied to debrominate the 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47), which achieved high conversion and rapid debromination of BDE-47 to less- or non-toxic forms. The reaction conditions were optimized by the addition of 100 mg/L ZVZ particles and 3 mmol/L AA at original solution pH= 4.00 using the solvent of methanol/H₂O (v:v= 4:6), which could convert approximately 94% of 5 mg/L BDE-47 into lower-brominated diphenyl ethers within a 90 min at the ZVZ/AA system. The high debromination of BDE-47 was mainly attributed to the effect of AA that inhibits the formation of Zn(II)(hydr)oxide passivation layers and promotes the corrosion of ZVZ, which leads to increase the reactivity of ZVZ. Additionally, ion chromatography and gas chromatography mass spectrometry analyses revealed that bromine ion and lower-debromination diphenyl ethers formed during the reduction of BDE-47. Furthermore, based on the generation of the intermediates products, and its concentration changes over time, it was proposed that the dominant pathway for conversion of BDE-47 was sequential debromination and the final products were diphenyl ethers. These results suggested that the ZVZ/AA system has the potential for highly efficient debromination of BDE-47 from wastewater.     

全氟辛烷磺酸盐(PFOS)对其它有机污染物在沉积物上吸附的影响

采用平衡振荡实验方法,研究了不同浓度的全氟辛烷磺酸盐(PFOS)对两种有机污染物(硝基苯和菲)在沉积物上吸附的影响.结果表明,单组分PFOS在沉积物上是非线性吸附;与其它有机污染物共存时,随着PFOS浓度的升高,硝基苯的吸附量先减少后增加,而菲的吸附量则先增加后减少.PFOS对其它有机污染物吸附的影响规律与有机污染物的...     

氰戊菊酯对斑马鱼和稀有鮈鲫不同生命阶段的毒性效应

为探明氰戊菊酯对鱼类不同生命阶段的毒性效应,以斑马鱼和稀有鮈鲫为测试生物,评价了氰戊菊酯对斑马鱼和稀有鮈鲫不同生命阶段的急性毒性差异。研究发现,氰戊菊酯对斑马鱼和稀有鮈鲫胚胎的96 h-LC50值分别为0.901(0.664~1.22)和0.636(0.233~1.74)mg·L~(-1)。氰戊菊酯对稀有鮈鲫胚胎孵化有明显的促进作用,染毒48 h后,0.188和0.375 mg·L~(-1)氰戊菊酯对稀有鮈鲫胚胎的孵化率分别为88.9%和100%。氰戊菊酯对斑马鱼仔鱼、幼鱼和成鱼的96 h-LC50值分别为0.00340、0.0183、0.00487 mg·L~(-1),氰戊菊酯对稀有鮈鲫仔鱼、幼鱼和成鱼的96 h-LC50值分别为0.0520、0.00277、0.00345 mg·L~(-1)。因此,氰戊菊酯对斑马鱼不同生命阶段的毒性从高到低顺序依次为:仔鱼成鱼幼鱼胚胎,氰戊菊酯对稀有鮈鲫胚胎、仔鱼、幼鱼和成鱼的毒性为幼鱼成鱼仔鱼胚胎。试验结果表明,斑马鱼仔鱼对氰戊菊酯的敏感性高于稀有鮈鲫相应的生命阶段,相对于斑马鱼,稀有鮈鲫胚胎、幼鱼以及成鱼对氰戊菊酯的毒性作用更为敏感,说明氰戊菊酯对斑马鱼和稀有鮈鲫不同生命阶段的毒性效应差异较大。     

有机膨润土对苯胺的吸附性能及应用研究

以溴化十六烷基三甲铵为改性剂制备有机膨润土，利用正交实验研究了有机膨润土吸附垃圾渗滤液中极性有机污染物苯胺的性能、条件及改性条件对吸附效果的影响。结果表明，有机改性膨润土对苯胺有很好的吸附效果，实验条件下对苯胺的去除率可达90％以上，绘制了有机膨润土吸附苯胺的吸附等温线，通过与吸附苯酚效果的比较，总结了有机膨润土吸附极性有机污染物的一般规律。